352 Professor T. Rupert Jones — The Enon Conglomerate 



one finds nortb-west of Heidelberg, The Enon Conglomerate of the 

 Oudtshoorn District closely resembles, in its lithological character 

 and relation to the older rocks, the similar deposits in the country 

 to the south of the Langebergen. Although determinable plant- 

 remains, with the possible exception of lignite, in which the minute 

 structure has been preserved, have not yet been found in the rock, 

 there are indefinite casts of fragments of wood in the sandstone near 

 Oudtshoorn, which are very like the casts in the sandstone of Cape 

 St. Blaize and Heidelberg." 



At p. 19 Dr. Corstorphine remarks : — "The character of the Enon 

 Series — thick banks of conglomerate, passing in most localities 

 within a short distance, vertically and horizontally, into coarse, 

 lenticular beds of sandstone, the latter containing stems and other 

 plant- remains, with fresh- water Esiheria, and in one instance 

 a coleopterous wing-cover — points to a fluviatile origin for the whole. 

 It is, with the exception of the recent sand-dune limestones and 

 other superficial deposits, the youngest formation in the area so far 

 surveyed." 



At p. 18 he states : — " Shales and claystone [?] also occur, 

 sometimes gray, sometimes black and almost coaly in appearance. 

 Near Herbertsdale and Heidelberg the shales are common, and at 

 the former locality they contain numerous plant-remains. At 

 Heidelberg a white shale [shaley arenaceous bed] occurs with 

 abundant Estheria casts." 



In March, 1899, I received from Mr. A. W. Rogers, one of the 

 Geological Surveyors of Cape Colony, three specimens of Enon 

 Conglomerate collected at Heidelberg, Swellendam District. Two 

 of the specimens (300 a and 302 a) consist of hard, white, laminated, 

 fine-grained sandstone (not argillaceous nor calcareous), showing 

 bed-planes, covered with flattened valves of Estheria. The other is 

 an irregular and slickensided fragment of similar siliceous rock 

 (296 a). A large part of it is not laminated, and the matrix seems 

 to have been crushed after consolidation ; it contains some imperfect 

 and indeterminable casts and fragments of valves, modified bj^ 

 pressure. These relics are distinguishable by their being stained 

 with yellow ochre. The rest of the piece is laminated, and the bed- 

 planes show many valves crowded together, flattened and modified 

 in their outlines. Their surfaces mostly present the appearance as 

 if the outer layer or film of shell had been dissolved or melted, as it 

 were, into a very thin, sometimes brownish varnish or glaze ; and 

 no reticulate or other ornament between the concentric ridges can be 

 discovered in these valves. 



Looking at the striking general similarity of the numerous 

 variable, sub-oblong, and sub-oval shapes in the crowds of extremely 

 flattened valves on these bed-planes, we evidently see the result of 

 shoals of probably one kind, or local tribe, of Estheria having been 

 suddenly enveloped in heavy deposits of mud ; and it is difficult to 

 distinguish any specific difference among the individuals. 



Venturing, however, to place them all under one quasi-specific 

 title, I group them as Estheria anomala, sp. no v. (Figs. 1-4). 



